A few years ago, when media pundits began discussing the possible ramifications of 500 channels of television, the concept of "narrowcasting" quickly became the buzzword
du jour. The idea was that programming in the future would be aimed at increasingly better-defined markets. Rather than an all-sports channel, an astute broadcaster would operate multiple channels devoted to individual sports: an all-basketball channel, for example, or round-the-clock motor sports. Advertising tailored for a tightly defined market might prove more efficient than its shotgun-effect equivalent.